Monday, August 20, 2007

Starboard float weighed

My starboard float weighs 144.8 lbs (65.6 kg), without hatches. I wasn't expecting great accuracy since I was using a couple of cheap Sunbeam bathroom scales, however we measured twice and got the same result both times.

In comparison, Ian had previously mentioned (in a F22 builders' update email) that the theoretical weight of one float is 112 lbs (51 kg), without paint (he didn't say if it was with or without hatches). Oliver once posted on the F-boat forum, that his float(s) weighed 132 lbs (60kg). So my float is obviously quite the porker. Some partial excuses for this are:
  • I was not stingy with the fairing putty, to say the least.
  • I put innumerable coats of primer on the float, in my quest for a fair surface.
  • My float has 2-3 lbs of wingnet rail on it; Oliver's didn't have this of course, and I doubt Ian accounted it in his 112lb target either.
  • This float is constructed almost entirely out of A550 corecell. The bulkheads on both floats are A400 (from my initial purchase of offcuts from Noah's), and the port-half of the port float is also A400. I assume Ian's estimate is for 100% A400. So my A550 probably accounts for at least an extra 5 lbs.

So: 144.8 lbs - well, it could have been better, could have been worse. Of course if I really cared about having a fast boat, I'd get my rear on a treadmill and lose a hundred pounds. :-)

Seriously though, it'd be interesting to hear what other builders have come up with for float weights.

Here's my son, helping me man-handle the floats in and out of the cradles on top of the scales:

When you're building a boat, it's often handy to have a strong, 6'4" 16 year old kid around the house. The downside is that he eats a lot. (Somewhere out there, my own father is laughing at me.)

Our weather today continued to be wet and cool and I was unable to spray the port float. However, the port float is now hanging in the tent, wiped-down with de-greaser, and only needs a final tack-off to be ready for spraying. Hopefully tomorrow is nicer.


Anonymous said...

Hi Jay,

Cool rainy weather is the best time for painting polyurethanes! The rain helps control and dust and fluff and the cool temperatures allow the paint to flow out better with less orange peel.

Phil Kite

Jay said...

Thanks for the tip Phil. The temperature the last couple days hardly got above 60 deg F -- and that is the minimum that Alexseal's paint literature says to spray under, with 77deg listed as "ideal". It's been dipping into the low to mid 50's at night as well. So I was basically being conservative, waiting for a day that got into at least the low 70's.

Funny how all of this epoxy and paint work turns a boatbuilder into a hyper-sensitive weather freak, if you happen to live in a non-ideal climate.


Edward said...

Looking good! You realize that being down here in Central Texas, I would almost kill for temperatures like you mention. It's been dipping into the 80's at night here.. brrrr!

- Ed